[PATCH] Documentation: x86: Fix obsolete name of page fault handler

From: Chin En Lin
Date: Mon Mar 14 2022 - 12:02:17 EST


Since commit 91eeafea1e4b ("x86/entry: Switch page fault
exception to IDTENTRY_RAW"), the function name of page
fault handler is out of date. This patch change
do_page_fault() to exc_page_fault().

Signed-off-by: Chin En Lin <shiyn.lin@xxxxxxxxx>
---
Documentation/x86/exception-tables.rst | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Documentation/x86/exception-tables.rst b/Documentation/x86/exception-tables.rst
index de58110c5ffd..0140a06b2705 100644
--- a/Documentation/x86/exception-tables.rst
+++ b/Documentation/x86/exception-tables.rst
@@ -32,14 +32,14 @@ Whenever the kernel tries to access an address that is currently not
accessible, the CPU generates a page fault exception and calls the
page fault handler::

- void do_page_fault(struct pt_regs *regs, unsigned long error_code)
+ void exc_page_fault(struct pt_regs *regs, unsigned long error_code)

in arch/x86/mm/fault.c. The parameters on the stack are set up by
the low level assembly glue in arch/x86/entry/entry_32.S. The parameter
regs is a pointer to the saved registers on the stack, error_code
contains a reason code for the exception.

-do_page_fault first obtains the unaccessible address from the CPU
+exc_page_fault first obtains the unaccessible address from the CPU
control register CR2. If the address is within the virtual address
space of the process, the fault probably occurred, because the page
was not swapped in, write protected or something similar. However,
@@ -281,12 +281,12 @@ vma occurs?

> c017e7a5 <do_con_write+e1> movb (%ebx),%dl
#. MMU generates exception
-#. CPU calls do_page_fault
+#. CPU calls exc_page_fault
#. do page fault calls search_exception_table (regs->eip == c017e7a5);
#. search_exception_table looks up the address c017e7a5 in the
exception table (i.e. the contents of the ELF section __ex_table)
and returns the address of the associated fault handle code c0199ff5.
-#. do_page_fault modifies its own return address to point to the fault
+#. exc_page_fault modifies its own return address to point to the fault
handle code and returns.
#. execution continues in the fault handling code.
#. a) EAX becomes -EFAULT (== -14)
--
2.25.1